1. Field of the Invention
The present invention belongs to the technical field of electrical apparatuses such as image forming apparatuses for forming an image on a recording medium and personal computers and, particularly relates to the technology of switching power modes in an electrical apparatus with a normal power mode for supplying power to respective parts of the electrical apparatus and a power saving mode for reducing a power supply amount as compared with the normal power mode.
2. Description of the Related Art
As a power saving technology in electrical apparatuses including image forming apparatuses for forming an image on a recording medium such as copiers and facsimile machines and personal computers, a technology of providing a power saving mode for reducing the amount of power supplied to respective parts of the electrical apparatus in addition to a normal power mode for supplying power to the respective parts is widely used. In this technology, a control is executed to switch the power supply mode of the electrical apparatus from the normal power mode to the power saving mode when the electrical apparatus has not operated for a predetermined time or when an instruction to switch to the power saving mode is input to the electrical apparatus.
For example, there has been proposed a technology of providing a storage unit for storing fixing temperatures (standby states) when no printing operation is performed in an image forming apparatus and successively selecting the standby states from the storage unit. The standby state means a state where power consumption can be suppressed although a time required to reach a fixing temperature at which an image forming operation is possible becomes longer as a non-printing time becomes longer.
For a user who does not use a printing function provided in an image forming apparatus much, for example, by making only several copies for every long period of time, it is thought not to be much advantageous to maintain a certain high fixing temperature. Even if it takes a relatively long time to increase the fixing temperature when the printing function with less frequency is utilized, an advantage brought about by reducing power consumption by reducing the supply of power required to maintain the fixing temperature is thought to be high.
However, in the above technology, the standby states corresponding to the non-printing time are successively selected from the storage unit. Accordingly, even if it is repeated that the image forming apparatus is not used for a long time after being used only for a short time, power has been consumed more than a little by the standby states successively selected until the long time elapses. That is, there has been room for improvement in reducing power consumption in electrical apparatuses.